Month: December 2015

You can configure Firefox to use Kerberos for Single Sign-on. In order for this functionality to work correctly, you need to configure your web browser to send your Kerberos credentials to the appropriate KDC.The following section describes the configuration changes and other requirements to achieve this.

In the address bar of Firefox, type about:config to display the list of current configuration options.

Enter the name of the domain against which you want to authenticate, for example, .example.com.

Repeat the above procedure for the network.negotiate-auth.delegation-uris entry, using the same domain.

Note

You can leave this value blank, as it allows Kerberos ticket passing, which is not required.

If you do not see these two configuration options listed, your version of Firefox may be too old to support Negotiate authentication, and you should consider upgrading.

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Figure 48.6. Configuring Firefox for SSO with Kerberos

You now need to ensure that you have Kerberos tickets. In a command shell, type kinit to retrieve Kerberos tickets. To display the list of available tickets, type klist. The following shows an example output from these commands:

The following represents the Oracle recommended method for automating database startup and shutdown of Oracle 9i instances on Linux, but it works equally well for Oracle 10g, 11G and 12c also. It can be used on any RHEL-style distribution, including Oracle Linux, up to an including RHEL7.

Once the instance is created, edit the “/etc/oratab” file setting the restart flag for each instance to ‘Y’.

TSH1:/u01/app/oracle/product/9.2.0:Y

Create a file called “/etc/init.d/dbora” as the root user, containing the following code.

⁠C.4. Setting the default JDK with the /usr/sbin/alternatives Utility

/usr/sbin/alternatives is a tool for managing different software packages that provide the same functionality.Red Hat Enterprise Linux uses /usr/sbin/alternatives to ensure that only one Java Development Kit is set as the system default at one time.

Important

Installing a Java Development Kit from the Red Hat Network will normally result in an automatically configured system. However, if multiple JDKs are installed, it is possible that /usr/sbin/alternativesmay contain conflicting configurations. Refer to Procedure C.4, “ Using /usr/sbin/alternatives to Set the Default JDK ” for syntax of the /usr/sbin/alternatives command.

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Procedure C.4. Using /usr/sbin/alternatives to Set the Default JDK

Become the root user.

/usr/sbin/alternatives needs to be run with root privileges. Use the su command or other mechanism to gain these privileges.

Set java.

Input this command: /usr/sbin/alternatives --config java

Next, follow the on-screen directions to ensure that the correct version of java is selected. Table C.1, “javaalternative commands” shows the relevant command settings for each of the different JDKs.

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Table C.1. java alternative commands

JDK

alternative command

OpenJDK 1.6

/usr/lib/jvm/jre-1.6.0-openjdk/bin/java

Sun Microsystems JDK 1.6

/usr/lib/jvm/jre-1.6.0-sun/bin/java

Set javac.

Enter this command: /usr/sbin/alternatives --config javac

Follow the on-screen directions to ensure that the correct version of javac is selected. Table C.2, “javacalternative commands” shows the appropriate command settings for the different JDKs.

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Table C.2. javac alternative commands

JDK

alternative command

OpenJDK 1.6

/usr/lib/jvm/java-1.6.0-openjdk/bin/javac

Sun Microsystems JDK 1.6

/usr/lib/jvm/java-1.6.0-sun/bin/javac

Extra Step: Set java_sdk_1.6.0.

The Sun Microsystems JDK 1.6 requires an additional command be run:

/usr/sbin/alternatives --config java_sdk_1.6.0

Follow the on-screen directions to ensure that the correct java_sdk is selected. It is /usr/lib/jvm/java-1.6.0-sun.

Lot of times when you just completed installation of an linux OS in a VM, you will find that you cannot access internet. There are two scenarios:

The host machine doesn’t need a proxy. In this way, please check if the network item on the upper right corner of VM is enabled. If not, enabling it should solve this issue.

The host machine is behind a proxy. In this scenario, you need to install cntlm. Do the usual steps of cntlm configuration and set up http_proxy environment.
To set up http_proxy to all users, edit file /etc/profile to add line:
export http_proxy=http://<hostname>:<portnumber>/, then try the following command to verify if it is successful:
wget http://www.google.com. If the page is successfully downloaded then congratulations; otherwise check your cntlm.conf file to see if the configuration is correct.